class Animal(object):
    pass

class Mammal(Animal):
    pass

class Bird(Animal):
    pass

#各种动物

class Dog(Mammal):
    pass

class Bat(Mammal):
    pass

class Parrot(Bird):
    pass

class Ostrich(Bird):
    pass


class Runnable(object):
    def run(self):
        print('Running')

class Flyable(object):
    def fly(self):
        print('flying')

class Dog(Mammal,Runnable):
    pass

class Bat(Mammal,Flyable):
    pass

dog=Dog()
dog.run()
